Webster's Revised Unabridged Dictionary · 1913

Convertible

Convertible , adjective

[Latin convertibilis: compare French convertible.]

1.
Capable of being converted; susceptible of change; transmutable; transformable.
Minerals are not convertible into another species, though of the same genus. — Harvey
2.
Capable of being exchanged or interchanged; reciprocal; interchangeable.
So long as we are in the regions of nature, miraculous and improbable, miraculous and incredible, may be allowed to remain convertible terms. — Trench